Shavlik, Jude W. and DeJong, Gerald F. 1990. “Learning in Mathematically-Based Domains: Understanding and Generalizing Obstacle Cancellations.”Artificial Intelligence 45(1–2): 1–45.
Towell, Geoffrey G. and Shavlik, Jude W. 1994. “Knowledge-Based Artificial Neural Networks.”Artificial Intelligence 70(1–2): 119–165.